Beam steering devices are used in lighting appliances for controlling the direction of a beam of light. This can, e.g., be done in a semi-static way, for changing the atmosphere of a room from time to time, or dynamically, for entertainment purposes. In combination with a tracking mechanism, beam steering can also be used for illuminating a moving object.
Previous beam steering technologies were based on mechanical devices such as motor actuated mirrors or lenses. Also known are beam steering devices utilizing electrically controllable liquid crystal based phased arrays or waveguides.
U.S. Pat. No. 5,151,814 discloses an optical beam scanner incorporating an array of liquid crystal based beam deflection elements. The deflection of the beam is accomplished by setting the phase tilt and the phase offset.